Chucking booster for turret lathes



,1 I w. w. JENKINS 2,366,903

CHUCKING BOOSTER.FOR TURRET LATHES V I Filed April 29, 1944 2 SheetS- -She et 1 INVENTOR.

W a a J 1945. w. w. JENKINS CHUCKING BOOSTER FOR TURRET LATHES Filed April 29, 1944 2 Sheets-Sheet 2 .mw \wwi.

Patented Jan. 9, 1945 h 2,366,993 onocxmesoosrenpron runner ,LATI-IES Willis 'vv. Jenkins, SeattleQWash, assignorfto WesternGear Works, Seart/tle'Wash, acorporat tion of Washington t Application April29, 1944,.Scrial No. 533,361

9Claims. (019279- 1) "This invention relates :to turret lathes, and more especially to the :feed :and chuck mechanism thereof as :it is employed to handle a :long piece of bar stock in successively bringing the stock forward required distances for a given operation 7 of machining each of a succession of 'bolts, studs, short "shafts or the like; the stock being clamped against axial movement following each said ad- Vance. 1

As its general object, the invention aims to de- 1 vise a. power attachment for the lathe arranged "and adapted to complement 'the standard handoperated control of the machines chuckand feed structure andwhichiis "so engineered as to act in harmony with the hand operation and pick up the load of a (toilet-closing action at that particu ,lar point when the operator reaches the hard sp0tfrequent1y termed the "fhump-of the stockgripping movement. This is tosay that the it inventionhas for iitsgeneral object toprovidea. structural assemb y. powered by compressed air or other suitable ,instruinentality, which {is normally inactive to the ,machines stock-gripping spring fcollets vbut which,at a given point einothe closing action, is brought into play to augment the hand force andthus promote tefiic'ienoy and speed by reducing the energy required to hem-anually expended in accomplishingQa closing of the colletover-the bar. v

With theforegoingend in views, the invention consists of a piston which is operatively interconnected with the hand-operated control lever of a. turret \lathes feed and chuck structure, a cylinder for the piston, a source of pressure fluid, ,valved connections :between the pressure ource and the cylinder, and controls for these valves; all so arranged and :adapted as to subject the piston to the "pressure influence of thesource only at a V given point in the cyclicmovement of thecontrol -.lever. i

.I'hinvention further consistsin the novel oon struction and the adaptation and combination of parts hereinafter described and claimed.

In theaccompanyingdrawings; t n 1 Figure 1 is s fragmentary :side *eleva-tional view of the stock-supporting end of a turret "lathe showing typical feediand-chuck mechanism, arts being broken vawayand shown :inlongitudinal ver. ticaltsection, and illustrating my :power attach- ,ment applied thereto, For :ma-ximumtclarity :in

an understanding of the invention it .is assumed ithatrthe controlling hand lever is being :moved :in thewdlrection indicated by the arrow and has ar- 'hardtspot of the chucking action has been encountered.

i 2 is a Inagmentary horizontalseotion t ken l-to a sliehtly enlarged scale .on broken line 22 of Fig. 1. t is- 31s ,a tr nsverse vertical section on :line 3 3t o f,Eig..2.

.Fig.,41is a-fragmen ry horizontal sectional view "taken an enlarged scale and detailing the 5 1 toted WiPiII -dQg which moves in unison with :the :hand lever of thet-machineiand acts ahfinger lever which in tumcon mls the air valve to cm t e (delivery of p essure air to the cylind o my power attachment. he finger-lever bein shown much th same position as indicated Fi 2, namelydepressed by the Wiper tovopen th {air valve :as the wiperhas beenmoved into-contact herewith as the hand lever approaches the e -v t-meme of its backward or toilet-clo ing movement.

5 is a Nielw {similar to; Fig; 4 excepting that the directive travel of the wiping-dog isshow reversed to portray themanner in which the :same is swung about its pivotal axis to tree the .iingerlever of itsdepressive tactioniand thushold the air yalveclosed throughout the period-of {the hand levers travel .in the opposite or forward-direction ofits reciprocal movemen, a 1

Fig. .6 is a sectional view detailing the spring- "closing fibleeder valve which -I employ in the pressure-air system (to .maintain tacondition of atmospheric pressure within the cylinder during ,periods when rthe air valve ,is closed; and

Ei E7 is a sectional view detailing theair valve n mployin dotted lines to indicate the asso- :ciated finger lever. It (may be pointed out that the finger 'lever is incorrectly shown as occupying to position disposed lengthwise tothe line of the valves ingress and egress pin s, distin u h d tfromttherelationshi-p as'itis illustrated in Figs. 1

through 3, inclusive, and which is {done with the ob ect of giving bettericomprehensionof theasso'ciation.

Clarity will perhaps abefladvanced belt-first describing the illustrated pa s of the lathe proper, and considering the operation thereoiwentirely by hand energy ds has been ,heretoforeqper iorm'ed, pointingn out that the present invention :in no Wise disturbs @either thep-mechanismtof the I machine or themanndr of usinst The structure as it is Fi .1 typifies feed :and chuck s ructure :as it customarily -en- 1 z 'ineered intosa turret lathe desi nedto handl lon ar wo k, thenumeral J10 tdenot zng the headstock end the letter W :thenlong piece of harsstock.

(rived at zthat point in its cyclic travel when the x55 ifrom which the given workis zbeimoduced,

said bar being clamped by spring collets to hold the same against axial movement and, as each machining operation is completed, freed from the grip of the collets and brought forward the required distance to expose a fresh length of bar, whereupon the collet fingers are again closed upon the same. The collets II, which are in sets selected according to the diameter of the rod or bar used, are of a self-expanding nature closed by subjection to the cramping influence of a fixed These levers are pivoted as at to a holder it which is in turn secured by screws ll -to a sleeve l8, the sleeve fitting over the tube and being held against endwise movement'by'the headstock. The actuating arms l4 of the toggle levers are ter- 'minally' fitted with rollers which, in the inactive position of the toggle levers, bear upon the surface of the sleeve, and operating upon such rollers to expand the arms I4 is a sliding cone 2|. This cone forms the nose of a spool 2|, and engaging in the peripheral groove of the spool are roller-studs 22 carried by yoke-arms 23' produced upon one end of a rocking beam 23 fulcrumed, as at 24, to a knee-bracket 25, the kneebracket being bolted to the frame of the lathe. The other end 25" of the rocking beam is also of furoate form and at its extremity finds swivel connection with the trunnion-pins 26' of an introduced block 26. Connecting by its rearend with'block 26, through the medium of a clamping collar 21-accornmodating endwise adjustment is a link 28, and the forward end of this link engages the crank arm 29' of a hand lever 29 fulcrumed as at 30 to the lathe frame.

There is provided, occupying a position between the fork-arms of the yoke 23" and operatively interconnected with the spoolfor unitary axial movement therewith, a travelling block 3 I receiving support from a reciprocally movable bar 32 a and having lost-motion connection with the latter to impart sliding movement thereto, thi bar being disposed below and parallel to the stock W and presenting a series of ratchet teeth which, in the forward travel of the bar, engage a pawl 33 motion'connection responsible for sliding the ratchet-bar in the forward movement of its reciprocatoryaction is indicated as comprising a key3'l, and it is usual, to accomplish a return movement, to employ a set screw (not shown) working in a slot cut in the bar.

To cursorily trace the operation of the describedfeed and chuck mechanism, assuming a machining operation to have beencompleted and it is desired to bring a following length of the stock W forward thedesired distance which will enable working, the operator-pulls the hand lever 29 forwardly to responsively slide the spool toward the headstock and which retracts the cone 2| permitting the arms l4 to contract, the elasticity of the collet reacting to release the workbar W and imparting slight endwise movement to the tube 13 returning the latter to its inactive position. This action takes place following move- .ment of the hand lever through a comparatively small part of its total travel, and during this period the block 3! rides freely upon the ratchet bar 32. Continued forward swing of the hand lever further retracts the spool 2| and, with it, the travelling block 3| to bring the latter into engagement with the key 31 and the ratchet is then made operative upon the pawl to advance or feed the stock W forwardly throughout the remaining swing of the lever. A following backward swing of the hand lever with corresponding reversal of the spools directive movement, and after a momentary free travel of the block 3| due to its lost-motion connection-with the ratchet bar,

picks up the latter and returnsthe bar, the pawl ratcheting freely during this return-travel; .As the hand lever nears the limit of its backward throw, the cone 2| is brought into engagement with the arms I4" and the start of a clamping action takes place, subjecting the operator to a comparatively heavy load as the toggle levers are initially brought into play and which slackens off as the rollers 20 are lifted off the sleeve l8 and onto the cone.

f It is the purpose of the present invention to substantially relieve the operator of this transitory load, and now proceeding to describe the same, it will be seen that I employ an oscillating air cylinder40 supported at its rear end by a swivel pin 4| carried upon the upper end of a bracket 42 boltably fixed to the lathe bed, additional support being brought down from the kneebracket -25 by bracing struts 43, one such strut being applied at each side of the cylinder. The mounting is such that the cylinder lies in the approximate horizontal plane of and to the rear of the rocking beams lower extremity, and saddling the latter and finding connection withthe trunnion pins 26' is the forked end of a 'rod 44 connecting by its opposite end with a piston 45 received in the cylinder, this piston rod being journaled ina cylinder head 40' which is imperforate excepting for a small vent 46. This vent, limiting escape of air fromin front of the piston as the latter nears the head 40', serves a cushioning oflice which will be understood in-the course of the following description, and there is provided in the wall of the cylinder, andso placed as to be uncovered by the travel of the piston as the block 2B'-in its forward travel reaches a of this hose attaches by a union 5| to the lateral outlet of a T- 52. Such T is normally exposed to the atmosphere through avalve body 53 which connects with one of the Ts two line-outlets, there being provided in this valve body a bleeder valve 54 opened under the influence of a spring 55. By its other line-outlet; and through a nipple 56, the T connects with the egress side -of avalve body 51. The valve 58 for this latter said body is .of the rapid-action typ and is opened against the pressure of a spring 60bydepressive action imparted to a stem 58'. Attached by a nipple 6| to theingress side of the valve body 5'l is a pressure regulator 62 fitted with i a pressure" gauge 63, and

a'fixed support by meanssuch as the U-bracket B1. to locate theexposed end of the stem 58 to one side of and at right, angles to the path traversed by the clamping collar 21 of the link 28, and applied to loosely bear againstthis exposed end by the influence of a minor spring 68 is a finger-lever carried by :a hinge-pin 1 I for movement about a vertical axis. Offset outwardly beyond the shank 1-12 of the finger-lever and dethrough T :52 and hostll into the cylinder, 1

piston 45 works ,upon the'rocking beam to fboost the spool 2| over the hard spot,and,lsubstantially coinciding as to time, the synchronized closing I of the valve 58 and opening of the blow-hole 41, 1 q

ing the bleedervalve 54 as pressure air rushes as the wiping-dogiclears the jog l2 and the piston advances beyond 'said blow-hole, isolates the cylinder from the pressure source and drops the pressure within the cylinder, the piston being cushioned in its slight furthermovement by the air trapped-other than for minor escape through scribing a shoulder-forming jog 12' ,atthe point of juncture, the freeend of said lever presents a flat," denoted by 'l2", and functional to said flat and by engagement therewith acting to depress the stem 58' and open the valve 58 against the pressure of the spring 50 is a wiping-dog I3 movable in reciprocatory rectilineal travel with the link 28, the arrangement being onein which the dogwipes the finger-lever, or which .is to say the flat thereof, in the forward direction of its reciprocatory travel while tracking freely over :thelflat in the return travel. More particularly described, said dog is fulcrumed, as at I4, within thel 'slot 15 of a lug formed upon a plate 16 which is boltably fixed to the clamping collar 21, and

is produced in the nature of .a bell-crank to present a rearwardly directed toe element 13". The

toe element is urged by.a spring 11 to normally foot upon the floor of theslot 15, and in this position locates, the wiping arm in functional relation to the flat.: l

The operation of the wiper will be well understood by an inspection of, Figs. 4 andfi. I As the dog moves with the plate 16in the forward directionindicated by arrow in Fig. 4, a.- wiping action takes place to depress stem 58'-and hold valve 58 open during theperiod in which the dog traverses the flat, the finger-lever being freed and valve 58 closing as the dog proceeds beyond the shoulder 12. A return movement; asindicated by the arrow of Fig. 5, trips the dog uponits con tact with the shoulden the dog being tilted into theillustrated position and being thereafter restoredby spring Hto its normal position as it clears the extremity :of, the finger-lever. The

gwiping action is timed tocoincide with the travel ,of the wiping-dog during that period of its move- ,ment in which the spool 2| is passingover the hard spot of a collet-closingraction. is

Now considering the operation of the handlever 29 with my attachment applied to thelathe, and assumingthatthe hand lever is being moved in a backward direction, the greaterp art of the swing proceeds as heretofore-entirely manualduring which time the piston,45 freely follows the forward movement of the trunnion block 26 in that the air in front of the piston is enabled, to readily escape through the blow-ho'lel'l and atmospheric air is fed into the cylinder, proper through hose 50, being permitted to pass the valve 54 which is held open by the spring 55, this spring subjecting the said valve to a pressure sufficiently below that to which the pressure regulator 62 is set asxto be readily overpowered by l the force of air which isto be delivered through the air valve upon an opening of thelatter. Continuing to moveth-e *handleverito a point where- Zat the cone 2| is, about to engage the toggle W levers, the wiping-dogwillhavebeenthen brought -into engagement with the finger-lever, and saidf vent 46-between the piston and the cylinder head The bleeder valve 54 willjhave opened simultaneously with, the blowing ofthe cylinder, enabling the piston'to be moved freely in its returr travel :aslit becomes again necessary to release the collet and, by the action of the f ratchet-bar, bring ,a freshlength of thestock W into position for machining. i i

, Departures from the embodiment of the invention which I have elected to illu'stratewill suggest f themselves, and no limitations areto be implied from the foregoing description having express reference thereto, itbeing my intention that all forms of construction and variations in detail coming within thetscope of the hereto annexed claims are to be considered as comprehendedby the invention. is What I claim is:

1 In along-bar turret lathe having reciproe cally movable and hand-energized control memher, and providing feed and chuck mechanism functional to the work-bar and connected for responsive action to the control member such, that the chucking action takes place only as [the i controlmember approaches the end limit of trave1 in one directionof reciprocationand the freeing of the work-bards eifectuated by movement inthe opposite direction through a correspond ing span of travel, said chuck mechanism being characterized in that thesarne ldevelops a hard spot transmitted to thecontrol member in, the

initial period of the latters said chuckingtravel,

power devices for relieving the operator of said encountered load of the hard spot, and comprising, in combination with the said mechanismand with the control member: a piston coupled to the control, member for movement relatively in unison therewith; a cylinder for the piston having a blow-hole in its: wall uncovered by the piston as the responsible control member, in its chuckchucking movement of the control member; a

, flow pipe; means normally inactive to the valve, 1 made responsiveto the movement of the control member, andoperatingupon thevalve to open,

normally closed Valve introduced in said fluid- V the latter only as the control member traverses said hard'spotof a chuckingactionj a second valve introduced in said fluid-flow pipe to occupy a position between the first-named valve and the cylinder and acting, when open, to relieve the pressure within the fluid-flow pipe; and a spring overpowered by thepressure of the source and acting upon the second-named valve to urge the i l latterinto its open'position.

2. In a long-baiturret lathe having a reciprocally movable and hand-energized control "member, and-providing feed and vchuck mechanism air valve 58opens assteni 58' is rdepressedflClosfunctional to the work bar and connected for responsive action to the control member such that the chucking action takes place only as the control member approaches the end limit of travel the control member: a piston coupled to the control member for movement relatively in unison therewith; a cylinder for the piston having a sidewall port exposed to the atmosphere and uncovered by the piston at that point in the chucking movement of the control member when the latter clears the hard spot; a source of pressure air; an

' airpipe from the pressure source to the cylinder for supplying air behind the piston as the latter moves in a chucking direction with the control member; a normally closed valve introduced in said air pipe; means normally inactive to the valve, made responsive to the movement of the control member, and operating upon the valve to open the latter, only as the control member traverses said hard spot of a chucking action; a second valve introduced in said air pipe to occupy position between the first-named valve and the cylinder and giving connection, when open, to the atmosphere; and a spring overpowered by the pressure of the source and acting upon the secondnamed valve to urge the latter into its open position.

I 3. In a long-bar turret lathe having a reciprocally movable and hand-energized control member, and providing feed and chuck mechanism functional to the work-bar and connected for responsive action to the control member such that the chucking action takes place only as the control member approaches the end limit of travel in one direction of reciprocation and the freeing or" the work-bar is effectuated by movement in the opposite direction through a corresponding span of travel, said chuck mechanism being characterized in that the same develops a hard spot transmitted to the control member in a stage of the latters said chucking travel, power devices a for relieving the operator of said encountered load of the hard spot and comprising, in combination with the said mechanism and with the control member: a piston coupled to the control member for movement relatively in unison therewith; a cylinder for the piston; a source of pressure air; an air pipe from the pressure source to the cylinder arranged to supply air behind the piston as the latter moves in a chucking direction with the control member; a normally closed valve introduced in the air pipe; means normally inactive to the valve, made responsive to the movement of the control member, and operating upon the valve to open the latter only as the control 7 member moves through its said chucking stage;

means for blowing the pressure air from the cylinder following a closing of said valve; a second valve introduced in said air pipe to occupy a position between the first-named valve and the cylinder and giving connection, when open, to the atmosphere; and means overpowered by the pressure of the source and acting upon the secondnamed valve to yieldingly urge the latter'into its open position.

4. In a long-bar turret lathe having a reciprocally movable and hand-energized control member, and providing feed and chuck mechanism functional to the work-bar and connected for responsive action to the control member such that the chuck mechanism is freed from the workbar and the latter brought forward in the lathe by movement of the control member through successive stages of its travel in one direction of reciprocation, and the chuck mechanism again made active to grip the work-bar by movement of the control member through that part of its return travel reversely coinciding with the workfreeing stage, power devices for relieving the operator of the starting load of a chucking operation and comprising, in combination with the said mechanism and with the control member: a piston'operatively interconnected with the control member formovement relatively in unison therewith; a-cylinder for the piston; a source of fluid pressure; a fluid-flow pipe from the source to the cylinder arranged to supply pressure fluid behind the piston considering the latter as moving with the control member toward its chucking stage; a normally closed valve for the fluid-flow pipe; means associated with the valve, governed automatically by the movement of the control member, and operating to open said valve throughout a partial period only of the control members said return travehsaidperiod including the start of a chucking stage and terminating short of the return limit of travel; and means acting to maintain a low-pressure condition within said cylinder during normal periods when the valve is closed.

I 511m combination with a member adapted to be shifted by hand energy,

mechanism acting to augment the handenergy for powering the'shiftable member in but one direction of its reciprocatory travel and only such as will carry the member over a given span of movement terminating short of the members full stroke, comprising a piston operatively interconnected with the member for movement relatively in unison therewith; a cylinder for the piston providing a blow-hole in itswall uncovered by the piston'as the latter occupies a position coinciding with the location of the shiftable member as the member clears said given span; a source of fluid pressure; a fluid-flow pipe from the source to the cylinder connecting with the cylinder to the rear of the piston when considering the pistons directive travel as the shiftable member moves through said given span; a normally closed valve for the fluid-flow pipe; means associated with the valve, governed; automatically by the movement of the shiftable member, and operating to open said valve only through the period when, the shiftable member is traversing said given span; a second valve introduced in said fluid flow pipe to occupy a position between the first-named valve and the cylinder and acting, when open, to relieve the pressure within the fluid-flow pipe; and means overpowered by the pressure of the source and acting upon the second-named valve to yieldingly urge the latter into its open position. a

6. In combination with a reciprocally movable member adapted to'be shifted by hand energy, mechanism acting to augment the hand energy for powering the shiftable member in but one direction of its reciprocatory traveland only such as will carrythe member over agiven span of reciprocally movable movement terminating short of the members full stroke, comprising a piston operatively interconnected with the member for movement relatively in unison therewith; a cylinder for the piston; a source of pressure air; an air pipe from the source to the cylinder connecting with the cylinder to the rear of the piston when considering the pistons directive travel as the shiftable member moves in said one direction of its reciprocatory travel; a valve for the air pipe; means responding to the movement of the shiftable member and acting to open said valve during traversal by said member of said given span while maintaining the valve in a closed position throughout the remaining reciprocatory travel of the member; a second valve introducedin said in said air pipe and normally occupying a closed position to isolate the source from the cylinder;

means responding to the movement of the shiftable member and operatively connected with the air pipe between the first-named valve and the cylinder giving access, when open, to the atmosphere; means overpowered by the pressure of the source and acting upon the second-named valve to yieldingly urge the latter into its openposition; and means independent of said last-named valve functioning to relieve the pressure within the cylinder at a point in the travel of the piston approximately coinciding with the closing of said first-named valve as the shiftable member clears said given span.

7. In combination with a reciprocally movable member adapted to be shifted by an energizing force of comparatively low intensity, mechanism acting to augment said force for boosting the shiftable member over a given span of movement in one direction only of its reciprocatory, travel and comprising: a piston operatively interconnected with the member for movement relatively in unison therewith; a cylinder for; the 1 piston; a source of pressure air; an air pipe from the source to the cylinder connecting with the cylinder to the rear of the piston when considering the pistons directive travel as the shiftable member moves in said one direction of its reciprocatory action; a valve introduced in said air pipe and normally occupying a closed position to 'isolate the source from the cylinder; means responding to the movement of the shiftable member and acting to open said valve only as the member traverses said given span; aconnection from the air pipe to the atmosphere in- V troduced between the valve and the cylinder; a

valve to open the latter only as the member traverses said given span; a connection from the air pipe to the atmosphere introduced between the valve and the cylinder; a valve for said lastnamed connection closed by subjection to the pressure of the source; means having a force characteristic less than the pressure of the source and acting upon the last-named valve to yieldingly urge the latter into its open position; and means independent of said connection to the atmosphere functioning to exhaust pressure air from within the air pipe and the cylinder as the shiftable member clears said given span, thus to drop the pressure within the air pipe below the force characteristic of the lastrecited valveopening means to enable the latter to exercise its influence to open the related valve. 9. In a long-bar turret lathe having a recip- [rocally movable and hand-energized control as the control member moves through its return,

stroke of reciprocation, said chuck being characterized in that the same transmits a hard spot to thecontrol member upon the initiation ofa chucking action, power devices operative upon the control member for boostin the latter over said transmitted'hard spot and comprising, in combination with the control member and with i the responding feed and chuck mechanismza source of pressure air; an air cylinder closed at bothends, having connection by one of its ends the cylinder, operatively connected forunitary the travel of the piston approximately coinciding with the closing of said first-named valve as the shiftable member clears said given span, the means last recited comprising a blow-hol provided in the wall of the cylinder.

8. In combination witha reciprocally movable member adapted to be shifted by an energizing force of comparatively low intensity, mechanism acting to augment said force for boosting the shiftable member over a given span of movement in one direction only of its reciprocatory travel and comprising: apiston operatively interconnected with the member for movement relatively in unison therewith; a cylinder for the piston; a source of pressure air; an air pipe leading from the source to the cylinder and connect outlet from the air connection to the atmosphere to the pressure source, and having its other end vented to the atmospherera piston received in movement with the control member, and acting by admission of pressure air to the cylinder to power the control member over said hard spot,

said cylinder providing a wall port giving access to the atmosphere and located in proximityof but spaced from the vented end of the cylinder and uncovered by the travel of the piston as the responding control member clears said hard spot? a normally closed valve introduced in said air connection acting, when closed, to isolate the source from the cylinder; means made respon- I sive to the movement of the control member and the control member traverses said hard spot; an

located between said valve and the ylinder; a valvefor said outlet closed by subjection to the pressure of the source; and means having a force characteristic ,less than the pressure of the source and acting upon the last-named valve to influence the same into its open position.

WILLIS W. JENKINS. 

